Äser dën neschene!

Are birthdays observed in Verduria? If so, how *does* one congratulate
someone on their birthday there? Different languages seem to use different
phrases, often fairly idiomatic and/or with interesting grammar.

For example, English just says "Happy Birthday". I'll presume that's
short for "I wish you a happy birthday", so the phrase would be in the
accusative. However, there's also "I wish you all the best on your
birthday", with a preposition ('on') that might not be easy to guess for a
foreigner.

Russian uses "Ya pozdravlyayu tebya s dnëm rozhdeniya" or "I
congratulate you(acc.) with day(instr.) of-birth(gen.)". That's especially
what I was thinking of when I mentioned "interesting grammar" above -- I
would not have expected a congratulating verb to take the
instrumental case for the occasion of congratulating. Also slightly
interesting is the use of the accusative with "congratulate" where German
and Greek use the dative. However, "to wish" does take the dative, for
example "Ya zhelayu tebe vsego samogo luchshego" ("I wish you(dat.)
all(gen.) most(gen.) best(gen.)"), which is again (to me) unusual for using
the genitive for what appears to be its direct object.

Hmm, I find that the English-Verdurian dictionary has the rather dull
Zula neschena!, which would be an accusative, short for something
like Len zurai zula neschena. I'm not sure if Irgend constructed
dën neschene or got it from something else I wrote... if the
latter, it's presumably because the neschena is technically the
celebratory meal when you were actually born, so that commemorations of
it would be dënî neschene.

I think the pagans would be more likely to annually commemorate one's
nacuy or redel, the adulthood ceremony. But since I'm not
a pagan, we don't have to worry about that. :)

"Dobre" in your first example should really be either accusative (to
match fsë, the object of zurai) or genitive ("all of good"). And
no preposition at all is required for time expressions, though de
is allowed. So I'd write Len zurai fsë dobrei dënán
neschene lë.